1
|
Olufemi AP, Fawole OG, Owoade OK, Popoola OAM, Jones RL, Toyeje AB, Abiodun PO, Omokungbe OR, Abiye OE, Sunmonu LA. Spatiotemporal distribution of pollutants and impact of local meteorology on source influence on pollutants' level in a traffic air-shed in Lagos megacity, Nigeria. ENVIRONMENTAL MONITORING AND ASSESSMENT 2023; 195:1126. [PMID: 37651046 DOI: 10.1007/s10661-023-11757-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Accepted: 08/19/2023] [Indexed: 09/01/2023]
Abstract
Pollution from vehicular emissions is a major cause of poor air quality observed in many urban and semi-urban towns and cities. As such, this study was conducted to assess air quality and the spatiotemporal distribution of vehicular and traffic-related pollutants in several air sheds of Lagos megacity, the economic nerve centre of Nigeria. A setup of low-cost air quality sensors comprising five (5) units was deployed between November 2018 and February 2019 within traffic corridors in the heart of the city. Diurnal variation of pollutants indicated that carbon dioxide (CO2) peaked during the early hours of the day, total oxide (Ox = NO2+O3) peaked at mid-day while carbon monoxide (CO) had two distinct peaks which correspond to morning and evening rush hours. Nitrogen dioxide (NO2) concentration peaked during evening hours. Average concentrations are NO2 (97.1 ± 9.7) ppb, Ox (78.6 ± 27.2) ppb, CO2 (450.1 ± 31.2) ppm, and CO (2285.63 ± 743.7) ppb. Average concentrations of pollutants were above thresholds set by the World Health Organization (WHO) except for NO2 which was within the range permissible limits. The implication of this is that the atmosphere is polluted due to elevated concentrations of airborne pollutants, an indication which is of both health and environmental concern. The air quality index (AQI) indicates that the quality of ambient air varies from good to very unhealthy for Ox, and unhealthy to very unhealthy for CO, while AQI for PM2.5 and PM10 showed hazardous at all the sampling locations except at UNILAG where it is unhealthy for the sensitive group. For all of the sampling sites, conditional bivariate probability function (CBPF) plots show a significant agreement with the location of known pollution sources.
Collapse
Affiliation(s)
- Ayodele P Olufemi
- Department of Physics, University of Medical Sciences, Ondo, Nigeria.
| | - Olusegun G Fawole
- School of the Environment, Geography and Geosciences, University of Portsmouth, Portsmouth, PO1 2UP, UK
- Environmental Pollution Research Laboratory, Department of Physics and Engineering Physics, Obafemi Awolowo University, Ile-Ife, 230001, Nigeria
| | - Oyediran K Owoade
- Environmental Pollution Research Laboratory, Department of Physics and Engineering Physics, Obafemi Awolowo University, Ile-Ife, 230001, Nigeria
| | | | - Roderic L Jones
- Department of Chemistry, University of Cambridge, Cambridge, CB2 1EW, UK
| | - Adekunle B Toyeje
- Environmental Pollution Research Laboratory, Department of Physics and Engineering Physics, Obafemi Awolowo University, Ile-Ife, 230001, Nigeria
| | - Pelumi O Abiodun
- Environmental Pollution Research Laboratory, Department of Physics and Engineering Physics, Obafemi Awolowo University, Ile-Ife, 230001, Nigeria
- Department of Civil Engineering, Morgan State University, Baltimore, USA
| | - Opeyemi R Omokungbe
- Department of Physical Sciences, Olusegun Agagu University of Science and Technology, Okitipupa, Nigeria
| | - Olawale E Abiye
- Centre for Energy Research and Development (CERD), Obafemi Awolowo University, Ile-Ife, Nigeria
| | - Lukman A Sunmonu
- Environmental Pollution Research Laboratory, Department of Physics and Engineering Physics, Obafemi Awolowo University, Ile-Ife, 230001, Nigeria
| |
Collapse
|
2
|
Alli AS, Clark SN, Hughes A, Nimo J, Bedford-Moses J, Baah S, Wang J, Vallarino J, Agyemang E, Barratt B, Beddows A, Kelly F, Owusu G, Baumgartner J, Brauer M, Ezzati M, Agyei-Mensah S, Arku RE. Spatial-temporal patterns of ambient fine particulate matter (PM 2.5) and black carbon (BC) pollution in Accra. ENVIRONMENTAL RESEARCH LETTERS : ERL [WEB SITE] 2021; 16:074013. [PMID: 34239599 PMCID: PMC8227509 DOI: 10.1088/1748-9326/ac074a] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Revised: 05/28/2021] [Accepted: 06/02/2021] [Indexed: 05/06/2023]
Abstract
Sub-Saharan Africa (SSA) is rapidly urbanizing, and ambient air pollution has emerged as a major environmental health concern in growing cities. Yet, effective air quality management is hindered by limited data. We deployed robust, low-cost and low-power devices in a large-scale measurement campaign and characterized within-city variations in fine particulate matter (PM2.5) and black carbon (BC) pollution in Accra, Ghana. Between April 2019 and June 2020, we measured weekly gravimetric (filter-based) and minute-by-minute PM2.5 concentrations at 146 unique locations, comprising of 10 fixed (∼1 year) and 136 rotating (7 day) sites covering a range of land-use and source influences. Filters were weighed for mass, and light absorbance (10-5m-1) of the filters was used as proxy for BC concentration. Year-long data at four fixed sites that were monitored in a previous study (2006-2007) were compared to assess changes in PM2.5 concentrations. The mean annual PM2.5 across the fixed sites ranged from 26 μg m-3 at a peri-urban site to 43 μg m-3 at a commercial, business, and industrial (CBI) site. CBI areas had the highest PM2.5 levels (mean: 37 μg m-3), followed by high-density residential neighborhoods (mean: 36 μg m-3), while peri-urban areas recorded the lowest (mean: 26 μg m-3). Both PM2.5 and BC levels were highest during the dry dusty Harmattan period (mean PM2.5: 89 μg m-3) compared to non-Harmattan season (mean PM2.5: 23 μg m-3). PM2.5 at all sites peaked at dawn and dusk, coinciding with morning and evening heavy traffic. We found about a 50% reduction (71 vs 37 μg m-3) in mean annual PM2.5 concentrations when compared to measurements in 2006-2007 in Accra. Ambient PM2.5 concentrations in Accra may have plateaued at levels lower than those seen in large Asian megacities. However, levels are still 2- to 4-fold higher than the WHO guideline. Effective and equitable policies are needed to reduce pollution levels and protect public health.
Collapse
Affiliation(s)
- Abosede S Alli
- Department of Environmental Health Sciences, School of Public Health and Health Sciences, University of Massachusetts, Amherst, MA, United States of America
| | - Sierra N Clark
- Department of Epidemiology and Biostatistics, School of Public Health, Imperial College, London, United Kingdom
- MRC Center for Environment and Health, Imperial College London, London, United Kingdom
| | - Allison Hughes
- Department of Physics, University of Ghana, Legon, Ghana
| | - James Nimo
- Department of Physics, University of Ghana, Legon, Ghana
| | | | - Solomon Baah
- Department of Physics, University of Ghana, Legon, Ghana
| | - Jiayuan Wang
- Department of Environmental Health Sciences, School of Public Health and Health Sciences, University of Massachusetts, Amherst, MA, United States of America
| | - Jose Vallarino
- Harvard T.H. Chan School of Public Health, Boston, MA, United States of America
| | - Ernest Agyemang
- Department of Geography and Resource Development, University of Ghana, Legon, Ghana
| | - Benjamin Barratt
- MRC Center for Environment and Health, Imperial College London, London, United Kingdom
- NIHR HPRU in Environmental Exposures and Health, Imperial College London, London, United Kingdom
| | - Andrew Beddows
- MRC Center for Environment and Health, Imperial College London, London, United Kingdom
- NIHR HPRU in Environmental Exposures and Health, Imperial College London, London, United Kingdom
| | - Frank Kelly
- MRC Center for Environment and Health, Imperial College London, London, United Kingdom
- NIHR HPRU in Environmental Exposures and Health, Imperial College London, London, United Kingdom
| | - George Owusu
- Department of Geography and Resource Development, University of Ghana, Legon, Ghana
| | - Jill Baumgartner
- Institute for Health and Social Policy, McGill University, Montreal, Canada
- Department of Epidemiology, Biostatistics, and Occupational Health, McGill University, Montreal, Canada
| | - Michael Brauer
- School of Population and Public Health, The University of British Columbia, Vancouver, Canada
- Institute for Health Metrics and Evaluation, University of Washington, Seattle, United States of America
| | - Majid Ezzati
- Department of Epidemiology and Biostatistics, School of Public Health, Imperial College, London, United Kingdom
- MRC Center for Environment and Health, Imperial College London, London, United Kingdom
- Regional Institute for Population Studies, University of Ghana, Legon, Ghana
| | - Samuel Agyei-Mensah
- Department of Geography and Resource Development, University of Ghana, Legon, Ghana
| | - Raphael E Arku
- Department of Environmental Health Sciences, School of Public Health and Health Sciences, University of Massachusetts, Amherst, MA, United States of America
| |
Collapse
|